Study On Extraction Purification And Antioxidant Activity Of Vitexin From Mung Bean Skin

Mung bean skin(MBS)is the seed skin after mung bean soaking and germination,which is called mung bean skin in medicine.The results showed that the antioxidant effect of mung bean was mainly provided by flavonoids in mung bean skin,and the vitexin content accounted for more than half.Therefore,in this paper,vitexin in MBS was extracted and purified,and its antioxidant activity was explored.The main results are as follows:1.Cellulase assisted APG(alkyl glycoside)combined with ultrasonic extraction of vitexin from MBS:Taking the extraction rate as the index,the extraction process was optimized by orthogonal test and response surface test on the basis of the best single factor.The optimum extraction process was obtained as follows:the ratio of liquid to material was 9:1,the amount of cellulase added was 0.4%,the temperature of enzymolysis was 50?,the time of enzymolysis was 60 min,the boiling water was used to kill the enzyme for 3 min,the extraction solution was retained,the filter residue was collected and 70%ethanol was added according to the ratio of 10:1,the APG concentration was added and adjusted to 0.5%,the p H was 8.5,and the soaking time was 2.5 h,and then ultrasounded at 350 W,50?for 50 min,combined the two extracts.The maximum extraction rate was 94.04%,which was consistent with the predicted value of the model,indicating that the optimization of the model was reasonable.2.The process of vitexin from MBS:compared with different types of macroporous adsorption resin for static adsorption analysis and comparison,the four optimal resins were determined as HPD100B,D-101,NKA-9 and XAD-16,and the best resin was determined as HPD100B by dynamic adsorption curve.Through the leakage curve and the single factor test,the best adsorption conditions were obtained:the concentration of the sample was 1.5 mg/m L,the p H of the sample was 4.5,the volume of the sample was2 BV,and the speed of the sample was 2.0 m L/min.The optimum analytical conditions are:70%ethanol content,5.0 p H,3 BV volume and 1.5 m L/min desorption rate.The main component of the extract was vitexin by HPLC.The concentration of vitexin from MBS before and after purification was 37.74%and 82.69%,respectively,which proved the good performance of the purification of vitexin by HPD100B macroporous adsorption tree.3.Study on the antioxidant activity of vitexin from MBS:the total reducing capacity of MBS increased with the increase of concentration in a certain range,and the IC₅₀ of scavenging DPPH free radical,hydroxyl free radical and superoxide anion free radical were 0.119,0.132 and 0.127 mg/m L,respectively,with strong antioxidant capacity.When the concentration of H₂O₂ was 900?mol/L,the survival rate was 51.32%,which was the best concentration.When the concentration of vitexin was 60-200?g/L,the survival rate was more than 110%.When the concentration was 60,80,100?g/L,the survival rate was significantly different(P<0.05).When the concentration was 100?g/m L,the survival rate was 131.68%;No matter before injury prevention or after injury treatment,different concentrations of vitexin significantly reduced MDA content in cells and culture medium,increased SOD,LDH,GSH,GSH-PX content,and there was a certain dose-dependent;when the drug concentration was 100?g/m L,the cell protection ability was almost the same as that of Vc group,indicating that vitexin had strong antioxidant ability.